Multi-layered support system

ABSTRACT

In various embodiments, a support system includes a multi-layer cover sheet with a number of layers. In certain embodiments, a source to move air inside and outside the multi-layer cover sheet can be provided. The source can include a source of positive pressure or negative pressure.

CROSS-REFERENCES TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional Patent ApplicationNo. 60/799,526, filed May 11, 2006 and U.S. Provisional PatentApplication No. 60/874,210, filed Dec. 11, 2006, which are incorporatedby reference herein without disclaimer.

FIELD OF THE INVENTION

The present disclosure relates generally to support surfaces forindependent use and for use in association with beds and other supportplatforms, and more particularly but not by way of limitation to supportsurfaces that aid in the prevention, reduction, and/or treatment ofdecubitus ulcers and the transfer of moisture and/or heat from the body.

BACKGROUND

Patients and other persons restricted to bed for extended periods incurthe risk of forming decubitus ulcers. Decubitus ulcers (commonly knownas bed sores, pressure sores, pressure ulcers, etc.) can be formed whenblood supplying the capillaries below the skin tissue is interrupted dueto external pressure against the skin. This pressure can be greater thanthe internal blood pressure within a capillary and thus, occlude thecapillary and prevent oxygen and nutrients from reaching the area of theskin in which the pressure is exerted. Moreover, moisture and heat onand around the person can exacerbate ulcers by causing skin maceration,among other associated problems.

SUMMARY

Exemplary embodiments of the present disclosure are directed toapparatus, systems and methods to aid in the prevention of decubitusulcer formation and/or promote the healing of such ulcer formation.Certain exemplary embodiments comprise a multi-layer cover sheet can beutilized to aid in the removal of moisture, vapor, and heat adjacent andproximal the patient surface interface and in the environmentsurrounding the patient. Certain exemplary embodiments provide a surfacethat absorbs and/or disperses the moisture, vapor, and heat from thepatient, as well as an air mover to facilitate a flow of air through thesurface. In addition, exemplary embodiments of the multi-layer coversheet can be utilized in combination with a number of support surfacesor platforms to provide a reduced interface pressure between the patientand the cover sheet on which the patient is positioned. This reducedinterface pressure can help to prevent the formation of decubitusulcers.

Exemplary embodiments comprise: a first layer comprising a vaporpermeable material; a second layer comprising a spacer material; a thirdlayer, wherein the second layer is between the first layer and the thirdlayer; and an air mover, wherein the air mover is configured to pull airthrough the spacer material and toward the air mover. In certainexemplary embodiments, the air mover is integral with the first layer orthe third layer. In certain exemplary embodiments, the air mover isconfigured to provide less than about 2.0 cubic feet per minute of airflow at a differential pressure of less than about 6.0 mm H2O and tocreate noise levels of approximately 30.0 db-A during operation. Inother exemplary embodiments, the first layer, the second layer, and thethird layer each comprise a first end, a second end, a first side, and asecond side; and the first layer and the third layer are bonded alongthe first end, the first side, and the second side. In other exemplaryembodiments, the aperture is proximal to the first end of the secondlayer; and at least a portion of the second end of the first layer isnot bonded to the second end of the third layer. In certain exemplaryembodiments, the air mover moves air between the first and second endsof the second layer during operation and the air mover is a centrifugalfan. In still other exemplary embodiments, the air mover is configuredto pull air or push air through the spacer material. In other exemplaryembodiments, the first layer may comprise a center section and two sidesections; and the center section has a higher vapor permeability ratethan the two side sections. In exemplary embodiments the spacer materialcomprises one of the following: open cell foam; natural or syntheticpolymer particles, filaments, or strands; cotton fibers; polyesterfibers; flexible metals and metal alloys; shape memory metals and metalalloys, and shape memory plastics. In still other exemplary embodiments,a zipper is coupled to either the first layer or the third layer. Incertain exemplary embodiments, an antimicrobial device is proximal tothe air mover.

Other exemplary embodiments may comprise: a flexible spacer material, ashell, and an air mover, wherein: the flexible spacer material is atleast partially encased in the shell; a first portion of the shell isvapor permeable; and the air mover is in fluid communication with afirst aperture in the shell and the air mover is configured to draw airthrough the spacer material. In certain exemplary embodiments, the airmover is integral with the shell. In other exemplary embodiments, asecond portion of the shell is liquid impermeable and the shellcomprises a second aperture distal from the first aperture, and thesecond aperture is open to the environment. In still other exemplaryembodiments, the air mover moves air between the first aperture and thesecond aperture and the spacer material comprises one of the following:open cell foam; natural or synthetic polymer particles, filaments, orstrands; cotton fibers; polyester fibers; flexible metals and metalalloys; shape memory metals and metal alloys, and shape memory plastics.In other exemplary embodiments, a zipper is coupled to the shell. Instill other exemplary embodiments, a antimicrobial device is proximal tothe air mover. In certain exemplary embodiments, the flexible spacermaterial is configured to permit air to flow through the flexible spacermaterial while the flexible spacer material supports a person laying onthe support system.

Other exemplary embodiments comprise a method of removing moisture vaporfrom a person, the method comprising: providing a support surface tosupport the person; and providing a cover sheet between the supportsurface and the person, wherein the cover sheet may comprise: a vaporpermeable material proximal to the person; a spacer material between thevapor permeable material and the support surface; and an air moverconfigured to push or pull air through the spacer material.

Other exemplary embodiments comprise a support system for supporting aperson, the support system comprising: an upper portion comprised of afirst spacer material that allows air to flow through the upper portion;a lower portion comprised of a second material that is air impermeable;an aperture in the second material; and an air mover configured to moveair through the aperture and the first material. In other exemplaryembodiments, the upper portion comprises a cover sheet that is vaporpermeable, liquid impermeable and either air permeable or impermeable.In still other exemplary embodiments, the lower portion comprises asupport material that permits air to flow through the support materialwhile the support material supports a person laying on the supportsystem. In certain exemplary embodiments, the lower portion furthercomprises a material that is vapor impermeable, air impermeable, andliquid impermeable, and the support material is between the secondmaterial and the material that is vapor impermeable, air impermeable,and liquid impermeable. In other exemplary embodiments, the aperturecomprises a substantially circular hole or slit in the second materialand the aperture is located near a torso or foot region of the lowerportion. In certain embodiments, the air mover pulls or pushes airthrough the first spacer material and through the aperture.

Other exemplary embodiments comprise: a cover sheet; a support member;and an air mover comprising an air inlet and an air outlet, wherein theair inlet is coupled to the cover sheet and the air outlet is coupled tothe support mattress. In embodiments where the air mover is used toinflate an air support mattress or direct air through an antimicrobialfilter, the air pressure and flow produced by the air mover may begreater than other embodiments that do not include an air supportmattress or antimicrobial filter. In certain exemplary embodiments, thecover sheet comprises a first layer that is moisture vapor permeable,water impermeable and either permeable or impermeable to air; the coversheet comprises a second layer that is an open, flexible material; andthe cover sheet comprises a third layer that is air, water, and moistureimpermeable. In other exemplary embodiments, the air mover is configuredto draw air through the cover sheet and exhaust air into the supportmattress. In certain exemplary embodiments, the air mover is external tothe support member, while in other exemplary embodiments, the air moveris integral to the support member.

Certain exemplary embodiments comprise: a vapor permeable upper portion;a lower portion comprising a spacer material encased within a shell; andan air mover that is integral with the shell. Certain exemplaryembodiments also comprise a support mattress, wherein the lower portionis between the vapor permeable upper portion and the support mattressand a shell that is liquid impermeable. Other embodiments comprise anopening proximal to the vapor permeable upper portion. In certainexemplary embodiments, the air mover is configured to draw air through avapor permeable, air permeable upper portion and the spacer material,while in other exemplary embodiments the air mover is configured toexhaust air through the spacer material and through a vapor permeableair permeable upper portion. In other embodiments, the upper portion isnot air permeable, and the air flow is provided by an opening in theshell.

Certain exemplary embodiments comprise: a first layer formed of a vaporpermeable material; a second layer formed of a flexible material, theflexible material to facilitate at least a flow of a vapor entering thesecond layer through the first layer; and a third layer formed of aliquid impermeable, gas impermeable, and vapor impermeable material.Specific exemplary embodiments also comprise an elongate memberextending from a first side toward a second side of the multi-layercover sheet, the elongate member to facilitate a flow of air through theelongate member and at least the second layer. In certain exemplaryembodiments, the second layer includes a first, second, and thirdsub-layer, the first and the third sub-layer comprising an attachmentsurface configured to attach to the second sub-layer. In specificexemplary embodiments, the second sub-layer has a higher permeability toair than the first and the third sub-layers. Certain exemplaryembodiments comprise a source of negative or positive pressure to moveair and the vapor inside and outside the multi-layer cover sheet. Incertain exemplary embodiments, the material forming the first layer isalso liquid impermeable and air impermeable. In certain exemplaryembodiments, the material forming the first, second, and third layersincludes a one-time use material for single patient use applications,while in other exemplary embodiments, the material forming the first,second, and third layers includes a multi-use material for multi-patientuse applications.

BRIEF DESCRIPTION OF THE DRAWINGS

While exemplary embodiments of the present invention have been shown anddescribed in detail below, it will be clear to the person skilled in theart that changes and modifications may be made without departing fromthe scope of the invention. As such, that which is set forth in thefollowing description and accompanying drawings is offered by way ofillustration only and not as a limitation. The actual scope of theinvention is intended to be defined by the following claims, along withthe full range of equivalents to which such claims are entitled.

In addition, one of ordinary skill in the art will appreciate uponreading and understanding this disclosure that other variations for theinvention described herein can be included within the scope of thepresent invention. For example, portions of the support system shown anddescribed may be incorporated with existing mattresses or supportmaterials. Other embodiments may utilize the support system in seatingapplications, including but not limited to, wheelchairs, chairs,recliners, benches, etc.

In the following Detailed Description of Disclosed Embodiments, variousfeatures are grouped together in several embodiments for the purpose ofstreamlining the disclosure. This method of disclosure is not to beinterpreted as reflecting an intention that exemplary embodiments of theinvention require more features than are expressly recited in eachclaim. Rather, as the following claims reflect, inventive subject matterlies in less than all features of a single disclosed embodiment. Thus,the following claims are hereby incorporated into the DetailedDescription of Disclosed Embodiments, with each claim standing on itsown as a separate embodiment.

FIG. 1 illustrates a cross-sectional side view of a first exemplaryembodiment of a support system for supporting a person.

FIG. 2 illustrates a top view of the lower section of the exemplaryembodiment of FIG. 1.

FIG. 2A illustrates a top view of a second exemplary embodiment of alower section.

FIG. 3 illustrates a cross-sectional side view of the lower section ofthe exemplary embodiment of FIG. 1.

FIG. 4 illustrates a cross-sectional side view of the upper section ofthe exemplary embodiment of FIG. 1.

FIG. 5 illustrates a cross-sectional side view of a second exemplaryembodiment of a support system for supporting a person.

FIG. 6 illustrates a side view of a third exemplary embodiment of asupport system for supporting a person.

FIG. 7 illustrates a side view of a fourth exemplary embodiment of asupport system for supporting a person.

FIG. 8 illustrates a perspective view of an exemplary embodiment of amulti-layer cover sheet.

FIG. 9 illustrates a cross-sectional view of the exemplary embodiment ofFIG. 8.

FIG. 10 illustrates a top down view of the first layer of themulti-layer cover sheet illustrated in FIGS. 8 and 9.

FIGS. 11 and 12 illustrate top views of various exemplary embodiments ofthe first layer of the cover sheet illustrated in FIGS. 8-10.

FIGS. 13A-13D illustrate various exemplary embodiments of a flexiblematerial of a multi-layer cover sheet.

FIGS. 14A-14D illustrate various exemplary embodiments of the secondlayer of the multi-layer cover sheet.

FIGS. 15A-115C illustrate various exemplary embodiments of themulti-layer cover sheet.

FIGS. 16A and 16B illustrate various exemplary embodiments of a systemof the present disclosure.

FIG. 17 illustrates a top view of an exemplary embodiment of the presentdisclosure.

FIG. 18 illustrates a side view of the exemplary embodiment of FIG. 17.

FIG. 19 illustrates a side view of an exemplary embodiment of thepresent disclosure.

FIG. 20 illustrates an end view of the embodiment of FIG. 19.

FIG. 21 illustrates a top view of an exemplary embodiment of the presentdisclosure.

FIG. 22 illustrates a side view of an exemplary embodiment of thepresent disclosure.

FIG. 23 illustrates a graph of operating data for a component of anexemplary embodiment of the present disclosure.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

Exemplary embodiments of the present disclosure are directed toapparatus, systems and methods to aid in the prevention of decubitusulcer formation and/or promote the healing of such ulcer formation. Forexample, in various embodiments, preventing ulcer formation and/orhealing decubitus ulcers can be accomplished through the use of amulti-layer cover sheet. Exemplary embodiments of the multi-layer coversheet can be utilized to aid in the removal of moisture, vapor, and heatadjacent and proximal the patient surface interface and in theenvironment surrounding the patient by providing a surface that absorbsand/or disperses the moisture, vapor, and heat from the patient. Inaddition, the exemplary embodiments of the multi-layer cover sheet canbe utilized in combination with a number of support surfaces orplatforms to provide a reduced interface pressure between the patientand the cover sheet on which the patient is positioned. This reducedinterface pressure can help to prevent the formation of decubitusulcers.

In various exemplary embodiments, the multi-layer cover sheet mayinclude a number of layers. Each layer may be formed of a number ofdifferent materials that exhibit various properties. These propertiesmay include the level of friction or shear of a surface, thepermeability of a vapor, a gas, a liquid, and/or a solid, and variousphases of the vapor, the gas, the liquid, and the solid, and otherproperties.

For example, in exemplary embodiments, the multi-layer cover sheet mayinclude materials that provide for a low air loss feature, where one ormore layers exhibit various air, vapor, and liquid permeable propertiesand/or where one or more layers are fastened together along variousportions of a perimeter of the multi-layer cover sheet to defineopenings through which air can move from inside to outside themulti-layer cover sheet, as will be described herein. As used herein, alow air loss feature of a multi-layer cover sheet includes, but is notlimited to: a multi-layer cover sheet that allows air and vapor to passthrough the first layer in the presence of a partial pressure differencein vapor between the internal and external environments of themulti-layer cover sheet; a multi-layer cover sheet that allows air andvapor to pass through the first layer in the absence of a partialpressure difference in vapor between the internal and externalenvironments of the multi-layer cover sheet; and a multi-layer coversheet that allows air and vapor to move into and/or out of themulti-layer cover sheet through the openings defined by portions of theperimeter that are fastened together.

In other exemplary embodiments, the multi-layer cover sheet can includematerials that provide for substantially no air flow, where one or morelayers include air impermeable properties and/or where layers arepartially fastened together along the perimeter of the multi-layercoversheet. In such exemplary embodiments, this configuration maycontrol the direction of movement of air from inside to outside (e.g.,under influence by a source of positive pressure) and from outside toinside (e.g., under influence by a source of negative pressure) themulti-layer cover sheet. Certain exemplary embodiments comprise amulti-layer cover sheet includes, but is not limited to, the following:a cover sheet that prevents or substantially prevents air from passingthrough the first layer, but allows for the passing of vapor through thefirst layer; a cover sheet that prevents or substantially prevents airfrom moving through the first layer in the presence of a partial vaporpressure difference between the internal and external environments ofthe multi-layer cover sheet, but allows for the passing of vapor throughthe first layer; and a cover sheet that prevents or substantiallyprevents air from moving out of the multi-layer cover sheet via thematerial forming a particular layer of the cover sheet, but allows airto move through the openings defined by portions of the perimeter of themulti-layer cover sheet that are fastened together.

In various exemplary embodiments, the multi-layer coversheet can includean elongate member extending from a side of the multi-layer cover sheettoward a different side of the multi-layer cover sheet. In exemplaryembodiments, the elongate member can be in fluid communication with asource to move air inside and outside the multi-layer cover sheet. Insome exemplary embodiments, the source to move air can include a sourceof positive pressure. In other exemplary embodiments, the source to moveair can include a source of negative pressure or reduced pressure.

In various exemplary embodiments, systems are provided that can includea number of components that both aid in prevention of decubitus ulcerformation and to remove moisture and/or heat from the patient. Forexample, systems can include a multi-layer cover sheet that can be usedin conjunction with a variety of support surfaces, such as an inflatablemattress, a foam mattress, a gel mattress, a water mattress, or a RIK®Fluid Mattress of a hospital bed. In such exemplary embodiments,features of the multi-layer cover sheet can help to remove moisture fromthe patient and to lower interface pressure between a patient and thesurface of the multi-layer cover sheet, while features of the inflatableor foam mattress can aid in the prevention and/or healing of decubitusulcers by further lowering interface pressures at areas of the skin inwhich external pressures are typically high, as for example, at bonyprominences such as the heel and the hip area of the patient. In otherexemplary embodiments, systems can include the multi-layer cover sheetused in conjunction with a chair or other support platform.

FIG. 1 discloses a general cross-section side view of upper section 120and lower section 140. As shown in FIG. 1, a support system 100comprises an upper section 120, a lower section 140, and an air mover110. In the embodiment shown, support system 100 is placed on top of asupport mattress 160, which supports a person 180. Subsequent figurespresent a more detailed view of the features of each section.

FIG. 2 shows a top plan view of lower section 140 without upper section120 in place, while FIG. 3 shows a detailed cross-section side view oflower section 140. In the embodiment shown in FIG. 3, lower section 140comprises a first layer 141, a second layer 142, and a third layer 143.In this embodiment, first layer 141 is comprised of a material that isliquid and air impermeable and either vapor permeable or vaporimpermeable. One example of such vapor permeable material is sold underthe trade name GoreTex™ GoreTex™ is vapor permeable and liquidimpermeable, but may be air permeable or air impermeable. Examples ofsuch vapor impermeable materials include sheet vinyl or sheet urethane.In the embodiment shown, second layer 142 is a spacer material thatallows separates first layer 141 and third layer 143. As used in thisdisclosure, the term “spacer material” (and related terms) should beconstrued broadly to include any material that includes a volume of airwithin the material and allows air to move through the material. Inexemplary embodiments, spacer materials allow air to flow through thematerial when a person is laying on the material while the material issupported by a mattress. Examples of such spacer materials include opencell foam, polymer particles, and a material sold by Tytex under thetrade name AirX™. Additional examples and features of spacer materialsare disclosed in the description of second layers 1041 and 3041 in FIGS.8-10 and 14B below. In the exemplary embodiment shown, third layer 143comprises a material that is vapor impermeable, air impermeable, andliquid impermeable. Examples of such material include sheet vinylplastic or sheet polyurethane material. In certain embodiments, firstlayer 141 and third layer 143 are connected at an interface 147 via aprocess such as radio frequency welding, heat sealing, sonic welding, orother comparable techniques. First layer 141 and third layer 143 may becomprised of the same material in certain embodiments.

As shown in FIGS. 2, 2A and 3, first layer 141 comprises one or moreapertures 145. Apertures 145 may be of various configurations, shapesand sizes. For example, apertures 145 may be slits or holes, and may bespaced in various configurations across first layer 141. In theembodiment shown in FIG. 2A, first layer 141 may comprise an aperture145 that is a single slit, while the exemplary embodiment shown in FIG.2 discloses substantially circular holes. In certain exemplaryembodiments, aperture 145 may be configured as a slit that is longenough to insert or remove spacer material 142 (described below) throughaperture 145.

Referring now to FIG. 4, a cross-section side view of upper section 120is shown. In the exemplary embodiment shown, upper section 120 comprisesspacer material 122 and a cover sheet 121. Spacer material 122 may becomprised of material equivalent to second layer 142 of lower section140 (shown in FIG. 3). In the exemplary embodiment shown, spacermaterial 122 is comprised of an material that can support the weight ofperson 180 and still allow air flow to pass through spacer material 122(while person 180 is laying on upper section 120 and upper section 120is supported by a mattress). In the exemplary embodiment of FIG. 4,cover sheet 121 is comprised of a material that is vapor permeable,liquid impermeable and either air permeable or impermeable. One exampleof such a material is GoreTex.™ In other embodiments, cover sheet 121can be vapor permeable, liquid permeable, and air permeable, such as acommon bed sheet.

Referring back to FIG. 1, support system 100 provides support for person180 and aids in the removal of moisture, vapor and heat adjacent andproximal the interface between person 180 and support system 100. In theexemplary embodiment of FIG. 1, support system 100 comprises air mover110 that is integral with lower section 140. In other exemplaryembodiments, air mover 110 may be external to lower section 140 withappropriate connecting members such as tubing, piping or duct work, etc.In certain exemplary embodiments, air mover 110 may comprise a guard orother partition (not shown) to prevent material from lower section 140or the surrounding environment from blocking the inlet or outlet of airmover 110. During operation, air mover 110 shown in FIG. 1 operates toreduce pressure within lower section 140 and create a suction air flow115 that is drawn through upper section 120 and lower section 140. Airmover 110 then exhausts air flow 117 into the surrounding environment.

In the exemplary embodiments shown in FIGS. 1-4, moisture vapor 116 istransferred from person 180 (and the air adjacent person 180) throughcover sheet 121 to air pockets within spacer material 122 of uppersection 120. Moisture vapor 116 will continue to transfer to air pocketswithin spacer material 122 while the air pockets are at a lower relativehumidity than the air adjacent person 180. As the relative humidity ofthe air pockets increases and approaches the relative humidity of theair adjacent person 180, the transfer rate of moisture vapor 116 willdecrease. It is therefore desirable to maintain a lower relativehumidity of the air pockets within spacer material 122 than the relativehumidity of the air adjacent person 180. As moisture vapor 116 istransferred to air pockets within spacer material 122, it is thereforedesirable to remove moisture vapor from the air pockets and lower therelative humidity of the air within spacer material 122. By removingmoisture vapor 116 from the air within spacer material 122, the transferrate of moisture vapor 116 from person 180 can be maintained at a moreuniform level.

In the exemplary embodiment shown in FIG. 1, suction air flow 115 flowsthrough the air pockets within spacer material 122 and assists inremoving moisture vapor 116 from the air pockets. This lowers therelative humidity of the air pockets and allows the transfer rate ofmoisture vapor 116 to be maintained over time. As shown in FIG. 4,suction air flow 115 may enter the air space within spacer material 122by flowing between cover sheet 121 and spacer material 122. In certainembodiments, suction air flow 115 may also flow through cover sheet 121.In the embodiment shown in FIG. 1, suction air flow 115 also travelsthrough apertures 145 of first layer 141, through second layer 142 andexits from air mover 110 as exhaust air flow 117.

In the exemplary embodiments shown in FIGS. 1-4, apertures 145 arelocated proximal to person 180, which may potentially increase themoisture vapor 116 transfer created by a given suction air flow 115. Thelocalization of suction air flow 115 to areas adjacent or proximal toperson 180 (and particularly in areas where moisture vapor 116 is moreprevalent), reduces the rate of suction air flow 115 for a required rateof moisture vapor 116 transfer. For example, if suction air flow 115were allowed to pass through the entire first layer 141 (rather thanrestricted to apertures 145), the amount of suction air flow 115 for agiven transfer rate of moisture vapor 116 from person 180 could beincreased. However, with apertures 145 restricting suction air flow 115to specific areas adjacent or proximal person 180, the rate of suctionair flow 115 may be reduced while the desired transfer rate of moisturevapor 116 is maintained. In certain exemplary embodiments, a desiredtransfer rate of moisture vapor 116 is maintained with a suction airflow 115 rate of approximately 1 cubic foot per minute.

The reduction in the amount of suction air flow 115 for a given transferrate of moisture vapor 116 reduces the size required for the air mover110. A sufficient reduction in the size of air mover 110 may allow forair mover 110 to be placed in locations that would otherwise not bepossible. In one embodiment, air mover 110 is a 12 volt DC, 40 mm boxfan such as a Sunon KDE 1204 PKBX-8. By utilizing an air mover such asthe Sunon model (or other similarly-sized devices), air mover 110 can beplaced integral to lower section 140, allowing for a more compactoverall design of support system 100. Air mover 110 may be coupled tolower section 140 with a substantially airtight seal so that air doesnot flow around air mover 110 as the air enters or exits lower section140. As shown in the embodiment of FIG. 1, air mover 110 may beincorporated into an area of lower section 140 that is near the end ofsupport mattress 160. By placing air mover 110 in a location that is notbetween support mattress 160 and patient 180, the comfort of patient 180should not be adversely affected. In other embodiments, air mover 110may be placed in other areas of lower section 140. For example, inembodiments where air mover 110 is sufficiently small, air mover 110 maybe placed between patient 180 and support mattress 160 without adverselyaffecting the comfort of patient 180.

A decrease in the required suction air flow 115 can also reduce theamount of energy required to operate air mover 110, thereby reducingoperating costs for support system 100. Reduced energy requirements andsuction air flow 115 for air mover 110 can also reduce the amount ofnoise and heat generated by air mover 110. A reduction in noise and heatcan provide a more comfortable environment for person 180, who may usesupport system 100 for extended periods of time.

A reduction in the size of air mover 110 may also lead to a reduction inthe cost of air mover 110. In certain embodiments, the cost of air mover110 may be low enough for air mover 110 to be a disposable item. Inaddition, upper section 120 and lower section 140 can be configured tobe disposable or reusable. In exemplary embodiments comprising reusableupper section 120 and lower section 140, the sections can be configuredso that they may be washed for disinfection. Additionally, in certainembodiments lower portion 140 and upper portion 120 can be attached toeach other through various fastening means, such as straps, snaps,buttons, or hook and loop fasteners.

In certain exemplary embodiments, apertures 145 are located and sized sothat the apertures 145 are concentrated near the torso or trunk ofperson 180 (i.e., the torso region of lower section 140). Such aconfiguration may be desirable if person 180 is more likely to producemore moisture vapor 116 in the torso region. Apertures 145 may also belocated near the feet of person 180 (i.e., the foot region of lowersection 140). Apertures 145 may also include additional openings nearother areas of person 180 that are likely to produce moisture vapor 116.

In certain exemplary embodiments, support mattress 160 and lower portion140 are approximately the same width and length. In other exemplaryembodiments, lower portion 140 may be narrower or shorter than supportmattress 160. For example, lower portion 140 may be dimensioned so thatapertures 145 are placed near the perimeter of lower portion 140 andunderneath patient 180. In certain exemplary embodiments, apertures 145may also be placed only near the center of lower portion 140. In stillother exemplary embodiments, apertures 145 may be placed both near thecenter of lower portion 140 and near the perimeter of lower portion 140.

Support mattress 160 can be any configuration known in the art forsupporting person 180. For example, in certain exemplary embodiments,support mattress 160 may be an alternating-pressure-pad-type mattress orother type of mattress utilizing air to inflate or pressurize a cell orchamber within the mattress. In other exemplary embodiments, supportmattress 160 does not utilize air to support person 180.

Referring now to FIG. 5, another exemplary embodiment of support system100 is shown in partial cross-section. This exemplary embodiment isequivalent to the embodiment disclosed in FIGS. 1 through 4, with theexception that the orientation of air mover 131 is reversed so thatsuction air flow 119 is pulled from the surrounding environment andexhaust air flow 118 is pushed through lower section 140 and uppersection 120. Apertures 145 reduce the amount of exhaust air flow 118needed to achieve the desired transfer rate of moisture vapor 116. Inthe exemplary embodiment shown in FIG. 5, moisture vapor 116 istransferred from person 180 through cover sheet 121 and to air pocketswithin spacer material 122 in the manner described above with respect toFIG. 1. In the embodiment of FIG. 5, however, exhaust air flow 118 flowsthrough air pockets in spacer material 122 and removes moisture vapor116. In the exemplary embodiment shown, a portion of exhaust air flow118 exits upper section 120 by flowing through the space between theperimeter of spacer material 122 and cover sheet 121. A portion ofexhaust air flow 118 may also flow through cover sheet 121.

Referring now to FIG. 6, an exemplary embodiment of a support system 200comprises a multi-layer cover sheet 210, a support mattress 220, and anair mover 230. In certain exemplary embodiments, support mattress 220 isan air-inflated mattress. Air mover 230 comprises an air inlet 232 thatis coupled to multi-layer cover sheet 210 via an inlet coupling member215. Air mover 230 also comprises an air outlet 234 that is coupled tosupport mattress 220 via a pair of outlet coupling members 225. Inletcoupling member 215 and outlet coupling members 225 may be comprised oftubing, flexible piping, or any other apparatus that allows air to flowbetween air mover 230 and multi-layer cover sheet 210 or supportmattress 220.

In the exemplary embodiment shown, outlet coupling members 225 are eachcoupled to separate chambers within support mattress 220. Therefore, theseparate chambers can be pressurized individually to facilitate movementof a person supported by support mattress 220. Such a configuration iscommonly known as an alternating pressure pad (APP). In other exemplaryembodiments, support mattress 220 may only have a single chamber and airmover 230 may have a single outlet coupling member 225 between air mover230 and support mattress 220. Support mattress 220 may therefore be analternating pressure pad type mattress, or any other type of mattressutilizing air to inflate or pressurize a cell or chamber within themattress. In certain exemplary embodiments, support mattress 220 mayincorporate pulsation by utilizing multiple pressure zones with discretebase line pressures that alternate to pressures above and below thediscrete base line pressure.

In the exemplary embodiment shown in FIG. 6, multi-layer cover sheet 210is equivalent to a cover sheet 1001 described with respect to FIGS. 8-10below. In the exemplary embodiment shown in FIG. 6, multi-layer coversheet 210 comprises a first layer 202 formed from a vapor permeablematerial, a second layer 204 formed from a spacer material, and a thirdlayer 206. In certain exemplary embodiments, third layer 206 is formedof a material that restricts air flow and directs the air flow airthrough the spacer material.

Support system 200 is configured so that during operation, air mover 230draws air through multi-layer cover sheet 210 and through second layer204 and also forces or pressurizes air into support mattress 220. Bycombining these functions, the costs, space requirements, electricalrequirements, and heat generation are reduced as compared to embodimentsthat utilize separate air movers to draw air through a cover sheet andforce air into a support mattress. Support system 200 therefore providesa compact and efficient system for inflating support mattress 220 andproviding air flow for multi-layer cover sheet 210 used in conjunctionwith a support mattress.

In the exemplary embodiment shown in FIG. 6, air mover 230 is externalto multi-layer cover sheet 210 and support mattress 220. In exemplaryembodiments with an external air mover, the air mover may beconveniently mounted in an accessible location, such as the foot boardof a bed frame supporting the cover sheet and support mattress.

FIG. 7 represents a side view of an exemplary embodiment. In thisexemplary embodiment, air mover 231 is incorporated into the outerenvelope or shell of support mattress 221. In the embodiment shown inFIG. 7, air mover 231 is integral to support mattress 221, therebyeliminating the need for coupling members between air mover 231 andsupport mattress 221. Because support mattress 221 is placed in closeproximity to multi-layer cover sheet 211, the length of a couplingmember 216 between air mover 231 and multi-layer cover sheet 211 mayalso be reduced. In the exemplary embodiment shown, air mover 231 iscoupled to support mattress 221 with a substantially airtight seal sothat air does not flow around air mover 231 as the air enters or exitssupport mattress 221. In still other exemplary embodiments (not shown),an integral air mover such as air mover 231 may be coupled to multipleoutlet coupling members that are coupled to multiple chambers withinsupport mattress 221.

FIGS. 8 and 9 illustrate a perspective view and a cross sectional view,respectively, of an exemplary embodiment of a multi-layer cover sheet1001. FIG. 10 illustrates a top view of the first layer of themulti-layer cover sheet 1001 illustrated in FIGS. 8 and 9. FIGS. 11 and12 illustrate top views of various embodiments of the first layer of thecover sheet illustrated in FIGS. 8-10. As best shown in FIG. 9, themulti-layer cover sheet 1001 includes three layers: a first layer 1021,a second layer 1041, and a third layer 1061. In various embodiments, thefirst, second, and third layers 1021, 1041, and 1061 each provide themulti-layer cover sheet 1001 with a variety of functions and properties,as will be described herein.

Multi-layer cover sheet 1001 illustrated in FIGS. 8-12 includes arectangular shape. In other exemplary embodiments, the multi-layer coversheet 1001 can include a number of other shapes including, but notlimited to, circular, ovular, square, polygonal, and irregular shapes.In addition, each of the layers of multi-layer cover sheet 1001 caninclude varying lengths, widths, and heights. In some exemplaryembodiments, for example, second layer 1041 can have a larger width thanfirst and third layers 1021 and 1061, and in other exemplaryembodiments, third layer 1061 can have a larger width than first andsecond layers 1021 and 1041.

In the exemplary embodiment illustrated in FIGS. 8-10, first layer 1021is formed of a vapor permeable, air permeable, and liquid impermeablematerial, second layer 1041 is formed of a laterally air permeableflexible material, and third layer 1061 is formed of a vapor, air, andliquid impermeable material. The vapor permeable material of the firstlayer 1021 allows for moisture vapor, heat, and the like, to passthrough the first layer 1021, in the form of vapor and/or air, and intosecond layer 1041 of the multi-layer cover sheet to thereby disperse andremove moisture and heat both from the patient and from the environmentsurrounding the patient, while preventing liquid from moving into thesecond layer 1041 via first layer 1021. In various embodiments, firstlayer 1021 can be formed such that all or a portion(s) of first layer1021 is permeable to air, vapor, and/or liquid. For example, as shown inFIG. 10, all of first layer 1021 is permeable to vapor, but impermeableto air and liquid. In FIG. 11, a seat region 1031 of first layer 1021 ispermeable to vapor and air, and a non-seat portion 1051 of first layer1021 is not air and vapor permeable. In addition, in various exemplaryembodiments, first layer 1021 can be formed such that some portions aremore permeable to vapor, air, and/or liquid than other portions. Asshown in FIG. 12, for example, seat region 1031 of first layer 1021 hasa permeability that is greater than a permeability of non-seat region1051 of the first layer 1021. As such, vapor and/or heat will transferthrough first layer 1021 at a higher rate in seat region 1031 than arate of vapor and/or heat transfer in non-seat regions 1051.

As one of ordinary skill in the art will appreciate, vapor and air cancarry organisms such as bacteria, viruses, and other potentially harmfulpathogens. As such, and as will be described in more detail herein, insome embodiments of the present disclosure, one or more antimicrobialdevices, agents, etc., can be provided to prevent, destroy, mitigate,repel, trap, and/or contain potentially harmful pathogenic organismsincluding microbial organisms such as bacteria, viruses, mold, mildew,dust mites, fungi, microbial spores, bioslimes, protozoa, protozoancysts, and the like, and thus, remove them from air and from vapor thatis dispersed and removed from the patient and from the environmentsurrounding the patient. In addition, in various embodiments, themulti-layer cover sheet can include various layers having antimicrobialactivity. In some embodiments, for example, first, second, and or thirdlayers 1021, 1041, and 1061 can include particles, fibers, threads,etc., formed of silver and/or other antimicrobial agents. Otherexemplary embodiments, including those disclosed in FIGS. 1-7 and 17-20may also comprise antimicrobial agents.

The first layer 1021 can include properties other than those illustratedand described in FIGS. 8 and 9. For example, in various exemplaryembodiments, first layer 1021 can be formed of a vapor permeable, andair and liquid impermeable material. In other embodiments, first layer1021 can be formed of an air, liquid, and vapor permeable material.Other combinations of properties exhibited by materials forming firstlayer 1021 are also contemplated. One example of a material that can beused to form first layer 1021 that exhibits vapor permeability, liquidimpermeability, and air permeability or impermeability includes amaterial under the trade name Gore-Tex®.

In various exemplary embodiments, second layer 1041 can be formed ofvarious materials, and can have a number of configurations and shapes,as described herein. In some embodiments, the material is flexible. Insuch exemplary embodiments, the flexible material can include propertiesthat resist compression, such that when the flexible material iscompressed, for example, by the weight of a patient lying on themulti-layer cover sheet, the flexible material has a tendency to returntoward its original shape, and thereby impart a supportive function tothe multi-layer cover sheet. The flexible material can also include aproperty that allows for lateral movement of air through the flexiblematerial even under compression.

Examples of materials that can be used to form second layer 1041 caninclude, but are not limited to, natural and synthetic polymers in theform of particles, filaments, strands, foam (e.g., open cell foam),among others, and natural and synthetic materials such as cotton fibers,polyester fibers, and the like. Other materials can include flexiblemetals and metal alloys, shape memory metals and metal alloys, and shapememory plastics. These materials can include elastic, super elastic,linear elastic, and/or shape memory properties that allow the flexiblematerial to flex and bend and to form varying shapes under varyingconditions (e.g., compression, strain, temperature, etc.).

FIGS. 13A-13D illustrate exemplary various embodiments of a flexiblematerial of the multi-layer cover sheet. In various embodiments of FIGS.13A-13D, the flexible material can include a number of cross-sectionalgeometric shapes, including but not limited to, circular, ovular,polygonal, and irregular geometric shapes. For example, as shown inFIGS. 13A-13D, the flexible material can include a strand member 2161, afoam member 2181, a coil member 2201, or a convoluted member 2221, or acombination thereof, each having a circular cross-sectional shape. Eachof the embodiments illustrated in FIGS. 13A-13D, either alone, or incombination, can provide support to the patient lying on the multi-layercover sheet, can aid in lowering interface pressures between the patientand the multi-layer cover sheet, and can permit air to flow under thepatient, and can function in combination with a support platform orsupport surface, such as an air mattress, to further reduce interfacepressures between the patient and multi-layer coversheet.

In each of FIGS. 13A-13D, the flexible material includes a first and asecond end 2241 and 2261. In various exemplary embodiments, first andsecond ends 2241 and 2261 can include surfaces and/or structures thatallow them to attach, connect, couple, hook, trap, and/or anchor toportions of the multilayer cover sheet to secure the flexible member tothe cover sheet, as will be described in more detail with respect toFIG. 14A. In some exemplary embodiments, the flexible material formingsecond layer 1041, illustrated in FIG. 9 is not coupled to multi-layercover sheet 1001, but rather is positioned between first and thirdlayers 1021 and 1061 and secured therein by fastening first and thirdlayers 1021 and 1061 together to thereby enclose second layer 1041, aswill be described herein below.

In exemplary embodiments, the flexible material can also facilitate atleast a flow of air through the second layer. For example, in variousexemplary embodiments, the flexible material can include configurationsthat define openings, channels, and passages that allow for air, vapor,and liquid to flow through the second layer. In one exemplaryembodiment, the flexible material can include a non-continuousconfiguration where individual components, such as individual strands orfibers, and other individual components are not connected to each other,but rather, are connected to one or more attachment surfaces orstructures defined by sub-layers of the second layer 104, as will bedescribed in connection with FIGS. 14A-14D.

FIGS. 14A-14D illustrate various embodiments of the second layer of themulti-layer cover sheet. In the embodiment illustrated in FIG. 14A,second layer 3041 includes a first sub-layer 3081, a second sub-layer3101, and a third sub-layer 3121. In this embodiment, first sub-layer3081 and third sub-layer 3121 can define a number of attachmentstructures or surfaces 3141 on which second sub-layer 3101 can attach.In various exemplary embodiments, second sub-layer 3101 can be, forexample, any of the flexible materials illustrated in FIGS. 13A-13D, orsecond sub-layer 3101 can be formed of other materials that provide botha supporting function to the patient and facilitate a flow of air underthe patient.

In various exemplary embodiments, the attachment surfaces 3141 caninclude inner surfaces and/or outer surfaces and/or openings of firstand third sub-layers 3081 and 3121 on which the flexible material candirectly attach, anchor, connect, etc, and through which air, vapor, andliquid can pass. In addition, first and third sub-layers 3081 and 3121can be formed of a number of different materials each having a rigid,semi-rigid, or flexible property.

FIG. 14B illustrates a cross-sectional view of an exemplary embodimentof second layer 3041 of multi-layer cover sheet 1001 illustrated in FIG.9. As shown in FIG. 14B, second sub-layer 3101 of second layer 3041includes a flexible material formed of a number of individual strandmembers 3161 extending between first and third sub-layers 3081 and 3121and attaching to first and third sub-layers 3081 and 3121 at variouslocations on first and third sub-layers 3081 and 3121. In thisembodiment, first and third sub-layers 3081 and 3121 also include aflexible material, such that all three sub-layers of second layer 3041can bend or flex under compressive forces. As shown in FIG. 14B, strandmembers 3161 define channels and openings 3281 within second sub-layer3101 that facilitate the movement of air, vapor, and liquid throughsecond layer 3041. In addition, openings (not shown in FIG. 14B) can bedefined by surfaces of first and third sub-layers 3081 and 3121 andthus, can also facilitate the movement of air, and/or vapor, and/orliquid therethrough. An example of a material that can be used to formsecond layer 3041 of the multi-layer cover sheet includes a materialunder the trade name AirX™ which is manufactured by TYTEX GROUP.

FIG. 14C illustrates a cross-sectional view of another exemplaryembodiment of the second layer 3041 of the multi-layer cover sheet 1001shown in FIGS. 8-12. As shown in FIG. 14B, the second layer 3041includes the first, second, and third sub-layers 3081, 3101, and 3121.The flexible material forming second sub-layer 3101 of second layer 3041includes a number of individual foam members 3181. Each foam memberincludes a porous or open cell structure that facilitates the movementof vapor, air, and liquid through foam members 3181. The foam membersinclude a spaced apart configuration to define passages or openings 3281that further facilitate the movement of air, vapor, and liquidtherethrough. In addition, openings 3301 defined by the first and thirdsub-layers 3081 and 3121 also facilitate the movement of vapor, air, andliquid therethrough.

In various exemplary embodiments of FIGS. 14A-14C, the flexible materialcan be chemically attached to the first and third sub-layers 3081 and3121 through the use of adhesives, and the like, and/or mechanicallyattached through the use of fasteners such as stitches, clasps, hook andloop, and the like, and/or physically attached through the use of welds,such as RF welds and related methods. As described herein, the shapesand sizes of the first, second, and third layers of exemplary embodimentof the multi-layer cover sheet, as well as sub-layers of the secondlayer can vary, and the exemplary embodiments illustrated in FIGS.14A-14C are not limited to rectangular shapes, as shown. Other shapesand sizes are contemplated and can be designed based upon the intendedapplication of the multi-layer cover sheet. For example, in variousexemplary embodiments, the shape and size of the cover sheet can bedesigned based upon the support surface or platform for which it is tobe used, such as a chair.

In the exemplary embodiment illustrated in FIG. 14D, the flexiblematerial of second layer 3041 includes a single foam member 3181 havingan open cell configuration. In this exemplary embodiment, single foammember 3181 is substantially the same perimeter size as the first andthird layers 102 and 104 of multi-layer cover sheet 1001 illustrated inFIGS. 8 and 9. In the exemplary embodiment illustrated in FIG. 14D, foammember 3181 can be positioned between first and third layers 102 and 106and secured by fastening first and third layers 102 and 106 to therebyenclose second layer 3041 within first and third layers 102 and 106 ofmulti-layer cover sheet 100. In various exemplary embodiments, foammember 3181 can include various sizes and shapes. For example, in someexemplary embodiments, single foam member 3181 has a perimeter that issmaller than the perimeter of the first and third layers 1021 and 1061.

Referring again to FIG. 9, in various exemplary embodiments, first andthird layers 1021 and 1061 can be fastened together such that the entireperimeter of the multi-layer cover sheet is fastened. In other exemplaryembodiments, a portion of the perimeter of first and third layers 1021and 1061 can be fastened, while remaining portion(s) can be unfastened.In such exemplary embodiments, fastened portions, which are adjacent tounfastened portions of the perimeter, define a number openings 1107-1 to1107-N (i.e., areas of the perimeter that are not fastened) throughwhich air and vapor can move. The fastening of first and third layers1021 and 1061 can include any number of techniques, including thosedescribed above in connection with fastening second layer 1041 to firstand third layers 1021 and 1061. For example, in some exemplaryembodiments, portions of first and third layers 1021 and 1061 arefastened together by stitching, while other portions are fastenedtogether through the use of one or more buttons and/or hook and loopfasteners (i.e., VELCRO@) or the like. In other exemplary embodiments,first and third layers 1021 and 1061 are fastened together by weldingthem together along their perimeters using high frequency radio energy(i.e., RF welding) or ultrasonic energy (i.e., ultrasonic welding).Other forms of welding are also contemplated.

In various exemplary embodiments, third layer 1061 can be formed of avariety of different materials that exhibit various properties. In theexemplary embodiment illustrated in FIG. 9, third layer 1061 is formedof a vapor impermeable, air impermeable, and a liquid impermeablematerial. The impermeable property of third layer 1061 prevents vapor,air, and liquid from passing through third layer 1061 and therefore,prevents exposure of the air, vapor, and liquid to a support surface orplatform, on which multi-layer cover sheet 1001 is positioned. Inaddition, third layer 1061 can function as a guide to direct the air,vapor, and liquid toward the openings defined by portions of theperimeter not fastened together, or to direct air from the openings andtoward an elongate member, as will be described herein. In variousembodiments, the third layer can also function as an attachment orcoupling layer to attach the multi-layer cover sheet to a supportsurface or platform. For example, in various embodiments, the thirdlayer can include extensions that can couple to the support surface suchas a foam mattress. In such embodiments, the extensions can be wrappedaround the support surface and tucked under the support surface or canbe attached to the support surface using a variety of fasteners, such asthose described herein. In other exemplary embodiments, the outersurface of the third layer can include a number of fasteners such as ahook and loop fasteners. In such exemplary embodiments, the supportsurface can be provided with a cover having a loop structure, and thethird layer can include an outer layer having a hook structure. Othermethods and mechanisms are contemplated for attaching the multi-layercover sheet to a support surface or platform so as to secure themulti-layer cover sheet thereto.

In various exemplary embodiments, multi-layer cover sheet 1001 can be aone-time use cover sheet or a multi-use cover sheet. As used herein, aone-time use cover sheet is a cover sheet for single-patient useapplications that is formed of a vapor, air, and liquid permeablematerial that is disposable and/or inexpensive and/or manufacturedand/or assembled in a low-cost manner and is intended to be used for asingle patient over a brief period of time, such as an hour(s), a day,or multiple days. As used herein, a multi-use cover sheet is a coversheet for multi-patient use that is generally formed of a vaporpermeable, liquid impermeable and air permeable or air impermeablematerial that is re-usable, washable, can be disinfected using a varietyof techniques (e.g., autoclaved, bleach, etc.) and generally of a higherquality and superior in workmanship than the one-time use cover sheetand is intended to be used by one or more patients over a period of timesuch as multiple days, weeks, months, and/or years. In various exemplaryembodiments, manufacturing and/or assembly of a multi-use cover sheetcan involve methods that are more complex and more expensive thanone-time use coversheets. Examples of materials used to form one-timeuse cover sheets can include, but are not limited to, non-woven papers.Examples of materials used to form re-usable cover sheets can include,but are not limited to, Gore-Tex®, and urethane laminated to fabric.

FIGS. 15A-15C illustrate various exemplary embodiments and components ofthe multi-layer cover sheet. FIG. 15A illustrates a perspective view ofa multi-layer cover sheet 400 having an elongate member 432 in fluidcommunication with a source 434 to move air. FIG. 15B illustrates anexemplary embodiment of the elongate member 432 in fluid communicationwith a source 434 to move air under positive pressure, for example, apositive pressure air pump 444. FIG. 15C illustrates an exemplaryembodiment of the elongate member in fluid communication with a source(e.g., a negative pressure air pump 446) to move air under negativepressure. Elongate member 432 functions to facilitate a movement of airinside elongate member 432, inside multi-layer cover sheet 400, andoutside multi-layer cover sheet 400, when elongate member 432 is coupledto positive pressure air pump 444 or negative pressure air pump 446. Forexample, in embodiments that include positive pressure air pump 444, apositive pressure is supplied to elongate member 432 to move air throughelongate member 432 and out of elongate member 432 for dispersion withinmulti-layer cover sheet 400, as will be described below in FIG. 15B.And, in exemplary embodiments that include negative pressure air pump446, a negative or reduced pressure is supplied to elongate member 432to move air into and through multi-layer cover sheet 400 and intoelongate member 432. In either case, movement of air is being providedto the multi-layer cover sheet that can create and maintain a partialpressure difference of vapor and thus, aid in moisture and heat removalfrom the patient and from the environment surrounding the patient.

In various exemplary embodiments, the use of negative pressure air pump446 can help reduce billowing of multi-layer cover sheet 400. Billowingcan occur when a mattress or cover sheet elevates or inflates in thelocation adjacent and proximal to the periphery of a patient's bodyunder the weight of the patient. Negative pressure produced fromnegative pressure air pump 446 can reduce the tendency of themulti-layer cover sheet to billow because the negative pressure tends tocause first layer 102 to lay flat against second layer 104 and thus, canaid or facilitate a flow of air directly under the patient as opposed toaround the patient, as can occur when a mattress or cover sheet billows.

As shown in the exemplary embodiment illustrated in FIG. 15A,multi-layer coversheet 400 includes elongate member 432. As describedherein, elongate member 432 can extend from a side of multi-layer coversheet 400 and toward the same side or a different side. In the exemplaryembodiment illustrated in FIG. 15A, for example, elongate member 432extends from a first side 436 toward a second side 438 of multi-layercover sheet 400. In some exemplary embodiments, elongate member 432 canextend from a third side 440 toward a fourth side 442 of multi-layercover sheet 400, or any combination of sides. As described herein, themulti-layer cover sheet can include various cross-sectional shapes, andthus, the number of sides can vary. As such, in various exemplaryembodiments, the elongate member can extend from a side toward adifferent side or multiple sides in exemplary embodiments having two ormore sides.

In various exemplary embodiments, elongate member 432 can be positionedat differing locations of multi-layer cover sheet 400. For example, insome exemplary embodiments, the elongate member can be positionedproximal or adjacent an inner surface (e.g., inner surfaces of the firstand third layers 404 and 408) of the multi-layer cover sheet 400 suchthat it extends from the first side 436 toward the second side 438 ofthe multi-layer cover sheet adjacent a length of the third side 440 ofmulti-layer cover sheet 400. In the exemplary embodiment illustrated inFIG. 15A, the elongate member 432 is positioned such that it extendsfrom the first side 436 toward the second side 438 in a linear manneradjacent the third side 440. In other exemplary embodiments, theelongate member 432 can be positioned such that it extends from thefirst side 436 toward the second side 438 in a non-linear manner, andalong a single plane or along various planes inside the multi-layercover sheet. For example, the elongate member can be positioned in anon-linear manner and along various planes within the multi-layer coversheet such that as it extends from the first side 436 toward the secondside 438 of the multi-layer cover sheet, it bends and turns in a numberof directions. In one exemplary embodiment, elongate member 432 extendsalong areas proximal and/or adjacent to surfaces of the first layer 404and/or second layer 406 in which moisture and or heat from a patient arepresent in higher concentrations relative to other portions of thepatient. Non-limiting examples of such areas include the seat region 103illustrated in FIGS. 11 and 12. As the reader will appreciate,positioning the elongate member proximal and/or adjacent to suchsurfaces (e.g., seat region 103) can help to increase the rate andefficiency of vapor and heat transfer from the patient because themovement of air within the elongate member will be proximal or adjacentto such surfaces, and thus a potentially higher partial pressuredifference of vapor can be created between the internal environment ofthe multi-layer cover sheet and the external environment outside themulti-layer cover sheet.

In various exemplary embodiments, the elongate member 432 can have avariety of cross-sectional shapes and sizes and can be configured in avariety of ways. For example, in exemplary embodiments, the elongatemember 432 can include, but is not limited to, circular, ovular,polygonal, and irregular cross-sectional shapes. In some exemplaryembodiments, the elongate member can be linear or straight as it extendsfrom the first side 436 toward the second side 438, as shown in FIG.15A. In other exemplary embodiments, the elongate member 432 can includea series of bends or turns as it extends from the first side 436 towardthe second side 438, as described herein. In various exemplaryembodiments, the elongate member 432 can include a size that equals alength of the multi-layer cover sheet 400 and in other exemplaryembodiments, the elongate member 432 can include a size having a lengthless than or greater than the length of the multi-layer cover sheet 400.

As shown in FIG. 15A, the elongate member 432 is positioned inside themulti-layer cover sheet 400. In some embodiments, the elongate membercan be positioned adjacent the multi-layer cover sheet outside themulti-layer cover sheet. And, in other embodiments, the elongate membercan be positioned at least partially within the multi-layer cover sheet,such that a portion of the elongate member extends to the outside of themulti-layer cover sheet.

The elongate member 432 can be formed of a single material or a varietyof materials and can have a number of different configurations.Materials to form the elongate member 432 can include, but are notlimited to, polymers, metals, metal alloys, and materials that includenatural and/or synthetic particles, fibers, filaments, etc., andcombinations thereof. Other materials can include flexible metals andmetal alloys, shape memory metals and metal alloys, and shape memoryplastics. Configurations can include one or more outer layers 448 and/orone more cores 450. The outer layer(s) 448 of the elongate member 432define a lumen 456. In some exemplary embodiments, the lumen 456 caninclude a core 450 positioned within the lumen 456. In variousembodiments of the elongate member, the outer layer and/or the core canbe designed to facilitate the movement of air through the elongate body.As such, in various exemplary embodiments, the outer layer and/or thecore can include configurations that define openings through which airand/or vapor, and/or liquid can pass.

In the exemplary embodiments illustrated in FIGS. 15B and 15C, theelongate member 432 has an outer layer 448 formed of a knitted or wovencover and a core 450 formed of a flexible material, such as the strandmember 216, the foam member 218, the coil member 220, and the convolutedmember 222 illustrated in FIGS. 13A-13D. In such exemplary embodiments,the core 450 can also include a multiple-layer configuration such as thethree sub-layer configuration of the second layer 3041 illustrated inFIG. 14A, where the second sub-layer is formed of a strand member, suchas strand member 216 illustrated in FIG. 13A. Other configurations arealso contemplated. For example, in some exemplary embodiments, the core450 can be formed of suitable spacer material and enveloped by the outerlayer 432.

As shown in FIGS. 15B and 15C, the elongate member 432 is in fluidcommunication with a source 444 or 446 to move air under either positiveor negative pressure. In the exemplary embodiment illustrated in FIG.15B, the source to move air under positive pressure is a positivepressure air pump 444. And, in the exemplary embodiment illustrated inFIG. 15C, the source to move air under negative pressure is a negativepressure air pump 446. Both the inflationary air pump 444 and vacuum airpump 446 are connected to a conduit 452, which in turn, is connected tothe elongate member 432. In various exemplary embodiments, connectingthe air pumps 444 and 446, the conduit 452, and the elongate member 432can be accomplished through the use of one or more connector components.For example, in some embodiments, the multi-layer cover sheet caninclude a connector component 454 coupled to a surface of themulti-layer cover sheet, the connector component 454 defines an openingbetween the internal environment of the multi-layer cover sheet 400 andthe external environment 464 surrounding the multi-layer cover sheet400. In such exemplary embodiments, the elongate member 432 can becoupled to the conduit 452 from inside the multi-layer cover sheet andthe connector component 454 can be coupled to the conduit 452 fromoutside the multi-layer cover sheet.

In various exemplary embodiments, surfaces of the elongate member 432can define a number of ports 458-1 to 458-N that allow air to enter orexit the elongate member 432. For example, in the exemplary embodimentillustrated in FIG. 15B, the inflationary air pump 444 forces air(indicated by arrows) through the elongate member 432, through ports458-1 to 458-N, and into the multi-layer cover sheet. And, in theexemplary embodiment illustrated in FIG. 15C, the vacuum air pump 446forces air from the multi-layer cover sheet and into the negativepressure air pump 446, where it is dispersed back into the environment.

As described herein, exemplary embodiments of the present disclosure caninclude a number of antimicrobial devices, agents, etc. Examples ofantimicrobial devices can include mechanical devices such as filters,energy devices such as ultraviolet light sources, and chemical agentssuch as antimicrobial coatings. Other antimicrobial devices and agentsare also contemplated.

For example, in the exemplary embodiment illustrated in FIG. 15C, anantimicrobial device 460 such as a filter can be utilized withmulti-layer cover sheet. In one exemplary embodiment, the filter ispositioned such that air passes through the filter prior to entering thenegative pressure air pump. In this exemplary embodiment, thepossibility of pump contamination is reduced. In various exemplaryembodiments, the antimicrobial device 460 can be positioned at one ormore of the following locations: inside the negative pressure air pump446, adjacent the negative pressure air pump 446, proximal the negativepressure air pump 446, and distal to the negative pressure air pump. Invarious exemplary embodiments, the filter can be designed to receive andcontain particulate and fibrous matter from the environment surroundingthe patient and inside the multi-layer cover sheet. In various exemplaryembodiments, and as described herein, this matter can includepotentially harmful pathogens.

FIGS. 16A and 16B illustrate various exemplary embodiments of a system570 of the present disclosure. In various exemplary embodiments of FIGS.16A and 16B, the system 570 can include a multi-layer cover sheet 532positioned on a support surface 572. In various exemplary embodiments,the multi-layer cover sheet can include the multi-layer cover sheetillustrated in FIGS. 8, 9, and 15A. In various exemplary embodiments,the support surface 572 can include a number of surfaces and supportplatforms. For example, support surfaces 572 can include, but are notlimited to, an inflatable mattress, a foam mattress, a gel mattress, anda water mattress. Other support surfaces and platforms include theAtmosAir® mattress, the TheraRest® mattress, RIK® Fluid Mattress, theBariKare® Mattress, which are commercially available and owned byKinetic Concepts, Inc., of San Antonio, Tex. Each of the family of beds,mattresses, and other support surfaces provide various features,therapies, and benefits to the patient, and each are incorporated hereinby reference.

In the exemplary embodiment illustrated in FIGS. 16A and 16B, themulti-layer cover sheet 532, the multi-layer cover sheet includes afirst layer 502 formed of a vapor permeable material, a second layer 504formed of a flexible material, the flexible material to facilitate atleast a flow of vapor entering the second layer 504 through the firstlayer 502, and a third layer 506.

In various exemplary embodiments, the system can also include a sourceto move air inside and outside the multi-layer cover sheet. In someembodiments, the source to move air can include a positive pressure airsource, such as the positive pressure air source 444 illustrated in FIG.15B. And, in other exemplary embodiments, the source to move air caninclude a negative pressure air source, such as the negative pressureair source 446 illustrated in FIG. 15C.

As shown in the exemplary embodiment of FIG. 16A, the system includes apositive pressure air source 544 in fluid communication with an elongatemember (not shown), such as the elongate member illustrated in FIGS.15A-15C. The positive pressure air source 544 forces air (indicated byarrow 580) through the elongate member and out of openings defined bysurfaces of the elongate member where it is dispersed inside themulti-layer cover sheet 532, as described herein. The movement of airwithin the multi-layer cover sheet creates a dry environment inside themulti-layer cover sheet 532. Heat and moisture on and around the patientcan be removed from the patient due to the partial pressure differencein vapor between the internal areas of the multi-layer and theenvironment 582 surrounding the patient. The moisture on and around thepatient has a tendency to move from the area of high concentration onand around the patient to the area of lower moisture concentrationwithin the multi-layer cover sheet. The movement of air within themulti-layer cover sheet, induced by the source of positive pressure 544,also moves the vapor which has passed through the first layer of themulti-layer cover sheet 532 and into the second layer, where it isdispersed into the environment via openings in the multi-layer coversheet, as described herein. As described herein, a partial pressuredifference can result in a flow of air to maintain a partial pressuredifference of vapor such that vapor flows from outside the multi-layercover sheet 532 to the inside of the multi-layer cover sheet 532 via thevapor permeable first layer.

As shown in the exemplary embodiment of FIG. 16B, the system 570includes a negative pressure air source 546 in fluid communication withan elongate member (not shown), such as the elongate member illustratedin FIGS. 15A-15C. The negative pressure air source creates a vacuum inthe internal areas of the multi-layer cover sheet, which moves air 580from outside the multi-layer cover sheet and into the multi-layer coversheet where it passes under the patient and into the elongate member ofthe multi-layer cover sheet. The elongate member transfers air 580 andvapor and/or heat toward an antimicrobial device and/or agent 560 andthen into the source of negative pressure 546. The treated air is thendispersed back into the environment by the source of negative pressure546. As described herein, the partial pressure difference can result ina flow of air to maintain a partial pressure difference of vapor suchthat vapor flows from outside the multi-layer cover sheet 532 to theinside of the multi-layer cover sheet 532 via the vapor permeable firstlayer.

Referring now to FIGS. 17-20, an exemplary embodiment of a cover sheet500 comprises a first end 502, a second end 504, a first side 506, asecond side 508. The exemplary embodiment shown comprises avapor-permeable top layer 510, an middle layer 520 comprising a spacermaterial, and a bottom layer 530. In this embodiment, cover sheet 500also comprises an aperture 535 in bottom layer 530 and proximal to firstend 502, as well as an air mover 540 in fluid communication withaperture 535. In the exemplary embodiment shown, aperture 535 and airmover 540 are located in a tab or extension 509 that allows air mover540 to be placed near the end of a supporting mattress 560 (as shown inFIGS. 19 and 20). In other embodiments cover sheet 500 may not comprisean extension for air mover 540.

The principles of operation for the exemplary embodiment disclosed inFIGS. 17-20 are similar to those of embodiments described above. Ingeneral, moisture vapor is transferred from a patient (not shown),through top layer 510, to air contained in middle layer 520. Air mover540 pushes or pulls air through middle layer 520 so that moisture vaporcan be removed from the air contained in middle layer 520. In certainexemplary embodiments, air mover 540 is a centrifugal 12 volt (nominal)DC fan manufactured by Panasonic under the part number FAL5F12LL. Thisparticular air mover is approximately 3 inches wide by 3 inches tall by1.1 inches thick and weighs approximately 3.5 ounces. This air moveralso produces a maximum air flow of approximately 8.8 cfm and maximumair pressure of approximately 6.2 mmH2O at a nominal 12 volts. Duringoperation, the air flow will be reduced as the pressure across the airmover is increased. Exemplary embodiments using this air mover typicallyhave an air flow of approximately 1.0 to 2.0 cfm during operation. Agraph of air pressure, air flow, nominal speed for various voltages isprovided in FIG. 23. As shown in FIG. 23, this air mover provides lessthan 6 mmH2O differential pressure at flow rates of approximately 2.0cfm. The Panasonic FAL5F12LL air mover also creates low noise levels(30.0 dB-A, according to the manufacturer's specifications).

In this exemplary embodiment, top layer 510 is bonded to bottom layer530 at first end 502 and at first and second sides 506 and 508. In theexemplary embodiment shown, top layer 510 and bottom layer 530 form ashell or envelope that substantially encases middle layer 520, but toplayer 510 and bottom layer 530 are not sealed around their entireperimeter. Such a configuration allows air to enter cover sheet 500 fromthe outside environment and flow through middle layer 520. As shown inFIG. 18, second end 504 is open, so that top layer 510 and bottom layer530 are not connected at second end 504, and middle layer 520 is exposedto the outside environment.

In the exemplary embodiment shown in FIG. 18, second end 504 may beconstructed so that middle layer 520 is exposed to the outsideenvironment along the entire second end 504. In other embodiments,second end 504 may be partially sealed (i.e. top layer 510 and bottomlayer 530 may be connected along a portion of second end 504) so that aportion of middle layer 520 proximal to second end 504 is exposed to theoutside environment. In certain exemplary embodiments, second end 504may be partially sealed so that a second aperture similar to aperture535 is provided at second end 504. In such embodiments, air mover 540may be placed at either first end 502 or second end 504 of cover sheet500. Such a configuration can provide flexibility in the configurationof cover sheet 500 by allowing air mover 540 to be placed at eitherfirst end 502 or second end 504, thereby allowing air mover 540 to beplaced at either the head end or the foot end of the patient. In otherembodiments, air mover 540 may be placed in a different location, andsecond layer 520 may be exposed to the outside environment in locationsother than first end 502 or second end 504.

In still other exemplary embodiments, first layer 510 and second layer530 may be comprised of the same material and configured to form a shellthat contains middle layer 520. In other exemplary embodiments, firstlayer 510 may comprise a section of material with high vaporpermeability in the center section (closest to a person's trunk) andmaterials with lower vapor permeability (and perhaps lower cost) in theside areas not directly underneath a person's trunk. In certainexemplary embodiments, first layer 510 may also be air permeable toallow air to flow through first layer 510 in addition to an openingbetween first layer 510 and third layer 530.

In exemplary embodiments, the portion of top layer 510 and bottom layer530 that is not bonded is distal from air mover 540. During operation,this can allow air mover 540 to push or pull air through a largerportion of middle layer 520 and remove more moisture vapor from middlelayer 520. In exemplary embodiments, cover sheet 500 may comprise aliquid impermeable layer. For example top layer 510 may be a vaporpermeable, liquid impermeable material such as GoreTex® or bottom layer530 may be a liquid impermeable material such as urethane. Otherexemplary embodiments may comprise different materials or combinationsof materials. The embodiment disclosed in FIGS. 17-20 may also compriseadditional features (such as antimicrobial devices, not shown) similarto those described with respect to other embodiments in this disclosure.

Referring now to FIGS. 21 and 22, another exemplary embodiment of acover sheet 600 comprises a zipper 650 and a second tab or extension 619with a second aperture 645 in addition to first extension 609 and firstaperture 635. The remaining aspects of the embodiment shown in FIG. 21are equivalent to those described in cover sheet 500 of FIGS. 17-20. Forexample, cover sheet 600 comprises a first end 602, a second end 604, afirst side 606, a second side 608, and first, second and third layers610, 620, and 630.

In the exemplary embodiment of FIG. 21, zipper 650 extends generallyaround the perimeter of cover sheet 600, but does not extend aroundextensions 609 or 619. In exemplary embodiments, zipper 650 is coupledto third layer 630 through any suitable means, such as stitching or RFwelding. In exemplary embodiments, zipper 650 is configured so that itmay be zipped to a corresponding zipper on a mattress or other supportsystem. In a specific exemplary embodiment, zipper 650 can be configuredto zip to a zipper on an AtmosAir® mattress provided by KineticConcepts, Inc. As shown in the side view of FIG. 22, cover sheet 600 maybe coupled to a mattress 660 via zipper 650. As shown, extensions 609and 619 extend beyond zipper 650 and hang at the end of mattress 660.

In certain exemplary embodiments, first layer 610 and third layer 630may be coupled (for example, by stitching or welding) at seam 615. Asshown in FIG. 21, seam 615 extends around the entire perimeter of coversheet 600, including extensions 609 and 619. Second layer 620, as wellas apertures 635 and 645 are inside the area surrounded by seam 615. Anair mover (not shown) can be coupled to either aperture 635 or aperture645 to provide negative or positive air pressure to the chamber createdby first layer 610, third layer 630, and seam 615. If a negative airpressure air mover is used, outside air can then be drawn from eitheraperture 635 or 645 (opposite of the air mover), drawn through secondlayer 620, and exhausted through the air mover. If a positive airpressure air mover is used, air can be pushed from the aperture that theair mover is coupled to, through second layer 620 and out of theaperture opposite from air mover. The embodiment disclosed in FIGS.21-22 may also comprise additional features (such as antimicrobialdevices, not shown) similar to those described with respect to otherembodiments in this disclosure.

1. A system comprising: a first layer comprising a vapor permeablematerial; a second layer comprising a spacer material; a third layer,wherein the second layer is between the first layer and the third layer;and an air mover, wherein the air mover is configured to pull airthrough the spacer material and toward the air mover.
 2. The system ofclaim 1 wherein the air mover is integral with either the first layer orthe third layer.
 3. The system of claim 1, wherein the air mover isconfigured to provide less than about 2.0 cubic feet per minute of airflow at a differential pressure of less than about 6.0 mm H2O.
 4. Thesystem of claim 1, wherein the air mover is configured to create noiselevels of approximately 30.0 dB-A during operation.
 5. The system ofclaim 1 further wherein: the first layer, the second layer, and thethird layer each comprise a first end, a second end, a first side, and asecond side; and the first layer and the third layer are bonded alongthe first end, the first side, and the second side.
 6. The system ofclaim 5 wherein: the second layer comprises an aperture is proximal tothe first end of the second layer; and at least a portion of the secondend of the first layer is not bonded to the second end of the thirdlayer.
 7. The system of claim 5 wherein the air mover moves air betweenthe first and second ends of the second layer during operation.
 8. Thesystem of claim 1 wherein the air mover is a centrifugal fan.
 9. Thesystem of claim 1 wherein: the first layer comprises a center sectionand two side sections; and the center section has a higher vaporpermeability rate than the two side sections.
 10. The system of claim 1wherein the spacer material comprises one of the following: open cellfoam; natural or synthetic polymer particles, filaments, or strands;cotton fibers; polyester fibers; flexible metals and metal alloys; shapememory metals and metal alloys, and shape memory plastics.
 11. Thesystem of claim 1 further comprising a zipper coupled to the either thefirst layer or the third layer.
 12. The system of claim 1 furthercomprising an antimicrobial device proximal to the air mover.
 13. Asystem comprising: a flexible spacer material; a shell, wherein: theflexible spacer material is at least partially encased in the shell; anda first portion of the shell is vapor permeable; and an air mover,wherein the air mover is in fluid communication with a first aperture inthe shell and the air mover is configured to draw air through the spacermaterial.
 14. The system of claim 13, wherein the air mover is integralwith the shell.
 15. The system of claim 13, wherein the air mover isconfigured to provide less than about 2.0 cubic feet per minute of airflow during operation at a differential pressure of less than about 6.0mm H2O.
 16. The system of claim 13, wherein the air mover is configuredto create noise levels of approximately 30.0 dB-A measured one meterfrom the air mover.
 17. The system of claim 13, wherein a second portionof the shell is liquid impermeable.
 18. The system of claim 13, whereinthe shell comprises a second aperture distal from the first aperture,and the second aperture is open to the environment.
 19. The system ofclaim 18, wherein the air mover draws air from the second aperture tothe first aperture.
 20. The system of claim 13 wherein the spacermaterial comprises one of the following: open cell foam; natural orsynthetic polymer particles, filaments, or strands; cotton fibers;polyester fibers; flexible metals and metal alloys; shape memory metalsand metal alloys, and shape memory plastics.
 21. The system of claim 13further comprising a zipper coupled to the shell.
 22. The system ofclaim 13 further comprising an antimicrobial device proximal to the airmover.
 23. The support system of claim 13 wherein the flexible spacermaterial is configured to permit air to flow through the flexible spacermaterial while the flexible spacer material supports a person laying onthe support system.
 24. A method of removing moisture vapor from aperson, the method comprising: providing a support surface to supportthe person; and providing a cover sheet between the support surface andthe person, wherein the cover sheet comprises: a vapor permeablematerial proximal to the person; a spacer material between the vaporpermeable material and the support surface; and an air mover configuredto pull air through the spacer material.
 25. A support system forsupporting a person, the support system comprising: an upper portioncomprised of a first spacer material that allows air to flow through theupper portion; a lower portion comprised of a second material that isair impermeable; an aperture in the second material; and an air moverconfigured to move air through the aperture and the first spacermaterial.
 26. The support system of claim 25 wherein the upper portioncomprises a cover sheet that is vapor permeable, liquid impermeable andeither air permeable or impermeable.
 27. The support system of claim 25wherein the lower portion comprises a support material that permits airto flow through the support material while the support material supportsa person laying on the support system.
 28. The support system of claim27 wherein the lower portion further comprises a material that is vaporimpermeable, air impermeable, and liquid impermeable, and the supportmaterial is between the second material and the material that is vaporimpermeable, air impermeable, and liquid impermeable.
 29. The supportsystem of claim 25 wherein the aperture comprises a substantiallycircular hole in the second material.
 30. The support system of claim 25wherein the aperture comprises a slit in the second material.
 31. Thesupport system of claim 25 wherein the aperture is located near a torsoregion or a foot region of the lower portion.
 32. The support system ofclaim 25 wherein the air mover pulls air through the first spacermaterial and through the aperture.
 33. A system comprising: a coversheet; a support member; and an air mover comprising an air inlet and anair outlet, wherein the air inlet is coupled to the cover sheet and theair outlet is coupled to the support mattress.
 34. The system of claim33 wherein: the cover sheet comprises a first layer that is moisturevapor permeable, water impermeable and either permeable or impermeableto air; the cover sheet comprises a second layer that is an open,flexible material; and the cover sheet comprises a third layer that isair, water, and moisture impermeable.
 35. The system of claim 33 whereinthe air mover is external to the support member.
 36. The system of claim33 wherein the air mover is integral to the support member.
 37. A systemcomprising: a vapor permeable upper portion; a lower portion comprisinga spacer material encased within a shell; and an air mover that isintegral with the shell.
 38. The system of claim 37 further comprising asupport mattress, wherein the lower portion is between the vaporpermeable upper portion and the support mattress.
 39. The system ofclaim 37 wherein the shell is liquid impermeable.
 40. The system ofclaim 37 wherein the shell comprises an opening proximal to the vaporpermeable upper portion.
 41. The system of claim 37 wherein the upperportion is also air permeable and the air mover is configured to drawair through the vapor permeable upper portion and the spacer material.42. The system of claim 37 wherein the upper portion is also airpermeable and the air mover is configured to exhaust air through thespacer material and through the vapor permeable upper portion.
 43. Amulti-layer cover sheet, comprising: a first layer formed of a vaporpermeable material; a second layer formed of a flexible material, theflexible material to facilitate at least a flow of a vapor entering thesecond layer through the first layer; and a third layer formed of aliquid impermeable, gas impermeable, and vapor impermeable material. 44.The multi-layer cover sheet of claim 43, further comprising an elongatemember, wherein: the elongate member extends from a first side toward asecond side of the multi-layer cover sheet; and the elongate member isconfigured to facilitate a flow of air through the second layer.
 45. Themulti-layer cover sheet of claim 43, wherein the second layer includes afirst, second, and third sub-layer, the first and the third sub-layercomprising an attachment surface configured to attach to the secondsub-layer.
 46. The multi-layer cover sheet of claim 45, wherein thesecond sub-layer has a higher permeability to air than the first and thethird sub-layers.
 47. The multi-layer cover sheet of claim 43, includinga source of negative pressure to move air and vapor inside and outsidethe multi-layer cover sheet.
 48. The multi-layer cover sheet of claim43, further including a source of positive pressure to move air andvapor inside and outside the multi-layer cover sheet.
 49. Themulti-layer cover sheet of claim 43, wherein the material forming thefirst layer is also liquid impermeable and air impermeable.
 50. Themulti-layer cover sheet of claim 43, wherein the material forming thefirst, second, and third layers includes a one-time use material forsingle patient use applications.
 51. The multi-layer cover sheet ofclaim 43, wherein the material forming the first, second, and thirdlayers includes a multi-use material for multi-patient use applications.